1. Field of the Invention
The present invention relates to an energy beam drawing apparatus and a method of manufacturing a device.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2009-049438 discloses a technique of decomposing and removing deposits such as carbon materials deposited on an optical member using hydrogen radicals in a charged-particle beam drawing apparatus serving as an exposure apparatus. Japanese Patent Laid-Open No. 2009-049438 also describes a technique of generating hydrogen radicals from hydrogen using at least one of a heatable filament, plasma generator, radiation source, and catalyst. Furthermore, in Kasai, “Electron Stimulated Desorption of H+ from Metal Surfaces”, Surface Science, Vol. 11, No. 5, pp. 274-280 (1990), there is disclosed a technique of generating hydrogen radicals by irradiating a catalyst with an electron beam while supplying hydrogen gas to the catalyst.
Japanese Patent Laid-Open No. 2009-049438 discloses a view that shows a case where hydrogen radicals are generated from hydrogen by a tungsten or tantalum hot filament heated to about 2,000 to 2,300 K. If the hot filament is positioned near an optical member on which a deposit has formed, the optical member is heated to be distorted, thereby decreasing the drawing accuracy. If the hot filament is positioned away from the optical member, the hydrogen radicals generated by the action of the hot filament are deactivated before reaching the optical member on which the deposit has formed, thereby decreasing the decomposition of the deposit. If a catalyst is used, the same problems arise.